The present invention relates to a device for a missile (or the like) which comprises a sustainer motor located at a distance from a rear surface of the missile, a motor nozzle arranged centrally in the rear surface, and a blow pipe which extends between the sustainer motor and the motor nozzle.
For defense purposes, enemy targets are often attached with the aid of guided projectiles or missiles. For example, such missiles may have a range of less than 5 km, and are generally quite small in size, with a diameter of between 100 and 150 mm. Known missile assemblies of this type usually include the following missile structure: wings, warhead, sustainer motor, gyroscope, battery, electronics, control members in the form of nozzle control members, and signal receiver or wire spool and tracer. When using nozzle control members, it is desirable to position the nozzle of the sustainer motor in a central portion of the rear surface of the missile. For the missile to maintain a stable movement during its trajectory, while also remaining easy to control, the aerodynamic centre of pressure must be behind and relatively near the centre of gravity of the missile. This requires the stabilization wings to be located in the vicinity of the centre of gravity of the missile. For the centre of gravity of the missile to remain fixed even after a powder charge of the propellant motor burns up, the powder charge of the propellant motor should also be located in the missile in such a way that the centre of gravity of the powder motor is near or coincides with the resulting centre of gravity of the missile. These two requirements, both of which must be fulfilled simultaneously, require the stabilization wings of the missile and the powder charge of the propellant motor to be located in the same portion of the missile, which is usually the middle portion. Certain apparatus, such as a warhead may be placed forwardly of the propellant motor, while other apparatus should be positioned between the propellant motor and the rear surface for proper functioning. Among such rearwardly positioned apparatus or components are the signal receiver or wire spool, and the nozzle control members and the tracers.
Assuming the wings of the missile, the propellant motor, warhead, nozzle control members, tracer and signal receiver are located in such a way that the resulting centre of gravity will be in the middle of the propellant charge, the conclusion arises that the remaining apparatus, including the gyro, electronics and battery must be located somewhere between the rear end of the propellant motor and the rear surface of the missile. However, in this space, a blow pipe extends from the rear end of the sustainer motor to the rocket motor nozzle, and if this pipe were to be arranged centrally through a longitudinal axis of the missile, the space available for the gyro, electronics and battery will be a ring-formed space between the centrally positioned tube and the inner surface of the missile body. If the outer dimension of the blow pipe, including its insulation, is assumed to have a diameter of 25 mm, the space for the gyro, electronics and battery will have a minimum dimension of 30-35 mm. While it is possible to design the electronics assembly and the battery so that there will be sufficient room for them in such a space, it is considerably more difficult to make room for a gyroscope in the remaining space, which is limited from a radial point of view. The miniature gyroscopes available in the market usually have a minimum diameter of between 50 and 60 mm. It is possible, of course, to design gyroscopes which can be installed in the ring-formed space available, but the costs of such a gyroscope will be many times greater than the costs of conventional miniature gyroscopes. In order to solve this problem, it has hitherto been proposed to over-dimension the missile from the point of view of the diameter, which, however, also involves increased costs.